Emissions monitoring at the old Tucker Beach tip is being beefed up because noxious gases may be endangering neighbouring residents.
Queenstown’s council has been monitoring four emissions bores within the boundaries of the closed landfill – three bores consistently exceed permitted methane and carbon dioxide levels.
Two of those bores record increasing emissions, ranging between 33 and 88 times the levels permitted under the landfill’s resource consent.
A report co-authored by Queenstown solid waste boss Stefan Borowy goes before today’s (Tuesday) meeting of the local council’s infrastructure services committee.
Borowy says landfill gas is about 40-60 per cent methane, with the rest mostly carbon dioxide, and the risks are flammability, asphyxiation, odour and greenhouse gas effects.
The 6ha Tucker Beach landfill closed in 1999 after an estimated 486,000 cubic metres of Wakatipu waste was dumped there over 37 years.
Last month, three additional gas monitoring bores were installed outside the landfill boundary – two on residential land and one on Tucker Beach road reserve.
Another three householders have also been approached about having bores installed to establish “whether a landfill gas risk currently exists within the confines of those properties”, Borowy reports.
Borowy recommends all bores should be monitored monthly for the next six months.
If emission limits continue to be breached, Queenstown’s council will have to spend $45,000 on “four additional passive vents” to reduce gas levels, Borowy warns.